Triumph LED installation guide

Introduction to installing your new LED rear light unit

Thanks for purchasing one of our new LED rear light boards for Triumph Bonneville, Bonneville SE, T100, Thruxton and Scrambler models. These step-by-step instructions will guide you through the installation process and electrical connections for your bike.

Installation is very straightforward as the LED board screws straight into the original mounting holes in place of the original bulb and reflector unit.

There is no cutting, drilling, soldering or other modification of the rear lamp unit required. Everything you should need is included with the supplied mounting kit. Electrical connections are made with the new 3M solder-free connections.

Please have a good read through all of these instructions before you start. Installation time is normally between about 10 and 15 minutes.

Before you start…

Installation shouldn’t take long, but it’s worth having the bike positioned so that you can comfortably access the rear light unit, somewhere dry and with decent light to work by. A quick clean of the rear light unit is worthwhile before you start to avoid getting dirt and grime over your shiny new LED light board.

As with any electrical work, it is worth disconnecting the battery (or at least removing the appropriate fuse and ensuring the power and lights are all switched off) to avoid making any accidental short circuits. You might however need to confirm the electrical connections for the brake and tail light power supplies, so it’s perhaps easier to leave the battery connected until its time to wire in the new light unit. Check that the ignition and all light switches are turned off though.

Step 1 – Removing the rear lens unit

The red plastic lens of the Triumph rear light unit is held in place with two obvious screws which can easily be removed using a flat-bladed screwdriver.

Once the screws have been withdrawn, the lens can be removed from the lamp unit. It is worth giving it a good clean at this stage, especially inside where dust can accumulate in all of the ridges and grooves which make up the diffuser pattern. An old tooth brush and some soapy water come in handy.

The two screws can be discarded as two new stainless steel hexagon headed screws are included as part of the kit. (Keep the old screws safe somewhere though if you think you might ever wish to go back to the original bulb fitment as the new screws are shorter than the originals).

Note that the two screws shown in the photo above are not the original Triumph ones. These were missing from the rear light unit I used to prototype the LED boards and which is shown in the pictures on this page. The actual screws have a coarser thread as they screw directly into the plastic rear shell of the light, whereas the ones shown in the photo have a standard M4 thread.

Step 2 – Removing the bulb and reflector

Next, remove the bulb by gently pushing it inwards and rotating by a few degrees anti-clockwise in the normal bayonet fitment style.

The ‘reflector’ is the shiny-silvered plastic parabola which focusses the light of the standard filament bulb out through the red rear lens. This is required for a filament bulb as these emit light evenly in all directions, however it is not required for the LED upgrade since these already have a focussed light output.

The reflector can therefore be removed by pulling it outwards from the main lamp unit. With the red lens removed, it is only held on by friction and should therefore come away quite easily. Take care not to damage the two plastic mounting posts as these are where the new LED board will also attach.

You will find that there are three wires going into the bulb holder on the rear side of the reflector. (Note that the colours will most likely be different to those shown in the photos in this guide). Gently ease the wiring out through the hole in the base of the lights rear shell so you have a few inches of play; you can leave the plastic reflector hanging by its wires as you ponder the next step.

There is no way to disconnect the wires from the bulb holder, so you will need to cut them with a pair of wire cutters or snips. But before you do, take note of which colours go where. You will notice that two of the wires go into the very end of the bulb holder; these are the power wires for the tail and brake light functions. The third wire goes to the side of the bulb holder underneath; this is the earth (or ground) connection for both circuits.

The tricky bit is determining which of the two power connections are for each of the brake and tail light functions. Some initial observations by customers on their own Triumph bikes suggest that the factory colour-coding is as follows:

Black – the ground connection on the side

Blue – the brake light power connector (on when you apply the brakes)

Red – the tail light power connector (on when the side or head lights are switched on)

Note that these are currently only observations from a couple of modern Triumphs, but it is likely that they will be common across most models and recent years of bike.

You can double check the connections using a multimeter; an extra pair of hands would also be useful at this stage! Set the multimeter to read voltage and select the 20v range (or else the smallest range above 12v). Touch the black (negative) to a bare metal surface of the motorcycle frame or engine, or very carefully to the ground terminal on the side of the bulb holder in the rear of the reflector.

Next carefully touch the red (positive) probe to one of the two power connectors at the end of the bulb holder. If you look down the hole from where the bulb has been removed you should see the two circular contacts. By getting your assistant to turn on and off the side lights, and apply the brakes to activate the brake light, you should be able to deduce which of the two power wires that go into the end of the bulb holder relate to each of the light functions. The multimeter should read around 12v when the appropriate light is on, and zero when it is off.

I would be grateful if you could let me know what you find (along with your year and model of bike) so that I can update these instructions as necessary for future customers. You can send me a message from here.

Once you are certain of your bikes particular colour code, make sure that the lights are all turned off again and preferably also disconnect the battery just to be sure of avoiding any accidental short circuits.

You can then cut the three wires allowing you to completely remove the reflector and bulb holder assembly. If you think you might wish to reinstall the original bulb holder at a later stage (perhaps if you were to sell the bike), then it is worth leaving a couple of inches of wire attached to the bulb holder to make reconnection easier. Otherwise cut the wires close to the bulb holder to give you as much length to play with as possible.

The reflector and bulb are not required for the LED light board upgrade. These can therefore be discarded, or else kept somewhere safe (along with the two original long lens screws) if you think you might wish to reinstall the original filament bulb setup at some point in the future.

Step 3 – Installing the mounting posts

With the reflector removed, you can now install the mounting posts that will position the LED light board within the rear light housing. There are four mounting posts supplied in the installation kit; two longer (12mm) posts and two shorter (10mm) posts.

Take the two longer (12mm) mounting posts and screw them by hand into the two plastic mounting posts in the rear shell of the light unit, as shown in the photo. The thread is the same as the two long mounting screws which we unscrewed in Step 1 to remove the red lens, therefore they should screw in easily. Take care not to cross or strip the thread in the plastic mounting posts.

Once fully screwed in by hand, the mounting posts can be carefully ‘nipped up’ a fraction of a turn using a 7mm spanner or socket. Again take care not to over-tighten or strip the thread in the plastic housing, especially if the rear lens has been removed a number of times in the past (for example, to change bulbs).

If you find that the thread is lose as a result of repeated screwing and unscrewing of the fixings, then you might find that a few wraps of plumbers (PTFE) tape around the thread of the mounting posts before installing might tighten them up.

If your light is very worn, a last-resort option might be to apply a small amount or glue to the threads of the mounting posts to ensure they don’t work lose. Sadly the Triumph lamp housing isn’t the best design and the plastic threads are a weak point, but it should be fairly easy to get a satisfactory fit of the mounting posts in this way even for the most worn of light units.

Step 4 – Making the electrical connections

The LED light boards are supplied with the new ‘3M Scotchlok’ style connectors to make the wiring connections very easy. No special tools, no soldering, no temperamental bullet connectors and no tricky screw terminals are required!

For conciseness in this instruction guide (and because the same connectors are used in some of our other products), a separate guide to using the 3M wiring connections is provided.

Note that the 3M connectors DO NOT require the insulation to be stripped back from the wires prior to insertion. If any of the wires from the bike or the LED board are stripped, cut the ends back so they are no longer bare.

The three wires from the LED board are colour-coded to match the typical Triumph factory colour-coding as described above, namely:

Black – the ground (earth) negative connection

Blue – the brake light positive power connector

Red – the tail light positive power connector

The connections are also marked on the back of the LED board to the right of the three-pin power connector. The top pin of the connector is marked ‘T’ for Tail-light, the middle one is marked ‘G’ for Ground and the bottom one is marked ‘B’ for Brake.

Once the three wires from the LED board connector have been connected to the three wires from the bike using the supplied 3M connectors, the power adapter can then be plugged into the LED board. The three-pin connector is designed to be a snug fit to prevent it ever unintentionally coming lose, so care is required when inserting the plug so as not to damage the internal contacts.

The best technique is to present the plug up to the connector on the LED board, then angle the tip down slightly so that the pins are hooked into their respective sockets. The plug can then be pushed gently home, levelling it back out as the pins go into the sockets.

If you find that any of the wires are pushed out the back of the plug by the pins on the LED board as it is pushed into place, remove the plug and push them back gently but firmly into place until you hear (or feel) a small click indicating they have locked into position.

Step 5 – Installing the LED board onto the mounting posts

We are now ready to install the LED light board onto the mounting posts in the rear light’s shell. Included in the installation kit are four plastic washers which will be fitted on either side of the LED board (front and back sides) to provide insulation, and also to help stop the mounting posts vibrating lose.

Put an insulating washer onto each of the two short (10mm) mounting posts, then push the mounting posts into the front of the LED board. Put the other plastic washers onto the mounting posts on the rear side of the LED board so that the board is sandwiched between the two sets of plastic washers.

The LED board can then be offered up to the rear light unit and screwed into place by hand. Feed any lose wire back into the shell of the light behind the LED board.

Once the outer (short) mounting posts have been screwed into the inner (long) mounting posts by hand, they can be nipped up using a 7mm spanner or socket. Again, take care not to over-tighten the posts so as not to damage the plastic mounting of the lamp unit. A second 7mm spanner is useful to hold the rear mounting posts stationary whilst tightening the outer ones into them (or a spanner on the rear and a socket on the front will also work).

With the LED board secured in place you can now reconnect the battery and test the tail and brake light functions. Double check that the brake light comes on when the brakes are applied, and the tail light functions (including the number plates and side position lights) come on when the headlights (and sidelights) are turned on. If the functions are reversed then you have most probably got the two power wires (the blue and red ones) connected to the bike’s wring the wrong way round.

Step 6 – Reassembling the rear light unit

The final step is to reassemble the rear lens unit. The original long slot-headed screws are replaced by two shorter stainless steel hex (Allen) headed screws. The two M4 spring washers go onto the hex screws first to provide vibration resistance.

Replace the red plastic rear lens and screw the two hex screws (with the spring washers fitted) into place using a 2.5mm Allen key. Double check that all of the wires are tucked behind the LED board so that they do not get trapped between the lens and rear shell of the light as you tighten the screws.

Also check that the rubber sealing strip which runs around the edge of the light’s shell is correctly seated so that the red lens compresses it into place. This provides the weather seal (waterproofing) for the light unit so it is important to check it is correctly in place, squeezed between the shell and lens of the light unit.

Tighten the screws sufficiently to compress the spring washers, but do not over-tighten. Inserting the long end of the Allen key into the screws and turning the shorter end by hand should provide about the required tightness.

And that’s it – installation of your new Triumph LED rear light upgrade is complete. Stand back and admire your handy work!

Conclusions and your comments

So that’s the installation complete and your new LED rear light board ready to give you many years of bright service. If you have any problems them please do not hesitate to get in touch via email or using the contact page. Please make sure your email address is correct so I can get back to you.

I would also be glad to hear how you found the installation process, any problems you encountered or anything that wasn’t clear or missing from this installation guide. Please let me know how I can improve the guide by leaving me a reply via the comment form below. Also if you have any photos you’ve taken of your bike during or after the installation process, then please email them to me so that I can add them to the customer’s photo gallery.

Finally, I would like to repeat my earlier request for you to let me know whether your bike had the same colour-coding of the wiring for the rear light as I described above. If it differed, please post a comment below with the correct colour-code for your bike. It would also be useful if you could include the year and model of your Triumph. Many thanks.
[disclaimer]

Customer’s installation photo gallery

Here are a few photos of the installation process sent in by previous customers who have fitted one of our new LED boards to their own modern Triumphs. Hopefully these help to show how the above instruction work in practice, and just how simple and quick the installation process actually is!

15 Responses to Triumph LED installation guide

Peter Derby26th September 2013

I installed my LED board on Monday, the day I received it. I am very impressed with the design and engineering of the unit (see my review elsewhere). There was one difference between my bike and the installation instructions. The screws that held the lens on were a coarse thread (I measured about 6 threads in 10mm) self tapping screw with a Phillips head. My bike is an 09 that I bought new, so I know the screws were the originals. I was able to thread the mounting posts into the plastic housing, but I had to use a wrench the whole way, applied a little pressure on the end of the post as I turned it, and was very careful. I suspect this might cause a problem for some folks.

Thanks Peter, both for your comments and great review on the product page. So good to receive feedback and glad you are so pleased with the LED board!

Regarding the lens screws, yes you’re right, these should be coarse threaded ones as you described. These were missing from the second hand lens I used as a template for designing the board, and hence the metric threaded replacement screws shown in the photos. I’ll add a note in the instructions above so this is clear.

As you mentioned, screwing in the mounting posts involves cutting a new thread in the plastic as this is different to the original screws holding the lens on. Depending upon how many times the lens have been removed in the past (to replace a blown bulb for example), this might be slightly tighter or looser. You could run a M4 tap in first if you have one to hand, but this is not usually necessary and screwing in the mounting posts will cut their own thread.

Wow. This LED set-up gives no excuse to the “I didn’t see you” rear-enders. Crazy bright, crisp light with both tail light and brake. Simple to install thanks to very detailed instructions. Only suggestion is to be VERY careful clipping the old wires to give you as much to work with when attaching the connector clips.

Hi Paul. Thanks for your kind words and feedback. Glad you’re pleased with the new LED board and found the install to be simple and straightforward.

Yes, that’s a good point with regards to snipping the wires. The cables seem to be quite tight on some bikes, so snip as close to the old bulb holder to give yourself as much slack to play with as possible.

Did the tail/brake LED board install today on my 2013 T100 Bonneville. My experience was much like other have reported hear. Except I did have an issue that I initially thought was a faulty LED board. No matter what I tried, I could not get more than a few of the centerally placed LED’s to illuminate as tail lights…and all would turn off with the brake switch actuation. After a long time testing stuff, I finally found the culprit…an incompletely compressed Scotch connector. A few careful presses home with my trusty pliers brought all the LEDs up as expected. I have this bike rigged up with a TailBlazer automatic brake flasher device (Kisan Inc.) and thought that might be the issue but it’s all good now…they play well with each other.

Got around to fitting the light board today.
Very straight forward to do….used solder and heat shrink for the wiring.
My 2006 T100 also has long self tappers for the lens fitting. No problem screwing in the M4 posts.Wiring colour code is the same,so no problem there either.

Pretty sunny here today…..but the stop and tail certainly seem clear and brighter than an LED bulb conversion. I’m more than happy with the result.
I’ll feel happier on my winter trips to Germany and Austria now 😉

Simple answer – no. A dealer has to demonstrate that a mod caused a problem. The act of modifying alone does not void a warranty.

James can best address any technical issues, but these mods are “passive” in that they are not changing the operation of other components of the bike. They are simply tagged onto the end of existing wiring. Electricity does not go backward.

Amazing fast delivery from Hong Kong to USA. Very well packed,the kit is marked very clearly.

The install:

The taillight is very easy to install, and the directions are great. As noted by others, the Triumph wires are very short. I did extend them by soldering on some slack but you do not need to do this.

The blinkers again very straight forward and the directions are spot on. The detail on the LED PC Board clearly shows the correct way to install them. (note the screw types/size per instructions) I must again note just how well the kit is packed and labeled as you go about the task.

The flasher relay there was a small snag in the install through no fault of James or this wonderful product. Triumph has made a change in relays, so if you have a VIN number beyond 521669 then the flasher relay has been changed to a 2-pin type without a ground connection and it’s not interchangeable with the earlier 3-pin relay.

This applies to all these models: Bonneville, Bonneville T100, Bonneville SE, Scrambler and Thruxton

For the T100 I can say you will not need the Diode kit, once you install the correct LED Flasher Relay.

James provided A+++ customer service and this really is a great improvement to the bike.

received the missing mounting hardware from you james, thank you! installation was easy and when the led tailight came on, i was in lighting nirvana. absolutely way brighter than stock. cost was reasonable and quality exceeded expectations. need is i say more? now debating going with the turn signals and head light on my bonneville also. again james, thank you for a quality product!

Matchless Clueless, thanks for the great product, easy and guided install and quality parts. I have a 2016 T100 and installed your “drop-in” LED rear light. All went as you instructed and wire leads were colored properly. Would love to buy your associated turn signals as well but cannot find them.

Hi Randy. Thanks for your kind words and glad you found the Bonneville LED rear light install simple and are pleased with the results! There seems to be some gremlins in the website’s menu system at the moment hindering navigation, but the turn signal kits can be found here:http://matchlessclueless.com/store/led-indicators/triumph-bonneville-led-indicator-set/
I’ll try and get the site navigation fixed later today…
Regards, James 🙂

I often visit your website and have noticed that you don’t update
it often. More frequent updates will give your blog higher rank
& authority in google. I know that writing articles takes a lot of
time, but you can always help yourself with miftolo’s tools which will
shorten the time of creating an article to a few seconds.